Now what I don’t understand is why AT&T would have a problem with this because

The calls come in & out over AT&T system (not as VoIP). Might be different if AT&T had free incoming calls, but they charge your minute allowance for both incoming & outgoing calls. (Yes, this may be different in the case of international calls, but I don’t make international calls so I lack a working knowlege of this functionality.)

You still get charged for the incoming text messages. I usually reply to them through the same way as I received them so AT&T gets their charges in that way too.

So why not call a number and have it bouncing to another number? Of course I use Google Voice primarily as a individual call blocking service so I may be a bit different user than they have in mind for their target demographic. But still, I’m still paying my AT&T bill & paid for the iPhone, let me use it with the services I want. Apple PUT IT BACK!